1. Field of the Invention
The present invention relates to a compact telephoto lens system with a large aperture.
2. Description of the Prior Art
Telephoto lens systems of this type which consist of three lens groups, namely a first positive, a second negative and a third positive lens group, and whose second lens group alone moves for focusing having been proposed for example in the following publications: Japanese Laid-Open Patent publications Nos. sho. 59-65820 and sho. 59-65821.
With the lens systems proposed in these Japanese publications, the first lens group consists of, from the object side, a first positive lens element, a second and a third positive meniscus lens element having a convex surface to the object and a fourth negative meniscus lens element. The third positive meniscus lens element and the fourth negative meniscus lens element are cemented with one another to leave no air space therebetween.